/*
 * Copyright 2019 the original author or authors.
 *
 * Licensed under the Apache, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at  http://www.gnu.org/licenses/lgpl-3.0.html
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.minidev.json.parser;

public class ParseException extends Exception {
    private static final long serialVersionUID = 8879024178584091857L;

    public static final int ERROR_UNEXPECTED_CHAR = 0;
    public static final int ERROR_UNEXPECTED_TOKEN = 1;
    public static final int ERROR_UNEXPECTED_EXCEPTION = 2;
    public static final int ERROR_UNEXPECTED_EOF = 3;
    public static final int ERROR_UNEXPECTED_UNICODE = 4;
    public static final int ERROR_UNEXPECTED_DUPLICATE_KEY = 5;
    public static final int ERROR_UNEXPECTED_LEADING_0 = 6;

    private int errorType;
    private Object unexpectedObject;
    private int position;

    public ParseException(int position, int errorType, Object unexpectedObject) {
        super(toMessage(position, errorType, unexpectedObject));
        this.position = position;
        this.errorType = errorType;
        this.unexpectedObject = unexpectedObject;
    }

    public ParseException(int position, Throwable cause) {
        super(toMessage(position, ERROR_UNEXPECTED_EXCEPTION, cause), cause);
        this.position = position;
        this.errorType = ERROR_UNEXPECTED_EXCEPTION;
        this.unexpectedObject = cause;
    }

    public int getErrorType() {
        return errorType;
    }

    /**
     * @return The character position (starting with 0) of the input where the
     * error occurs.
     */
    public int getPosition() {
        return position;
    }

    /**
     * @return One of the following base on the value of errorType:
     * ERROR_UNEXPECTED_CHAR java.lang.Character ERROR_UNEXPECTED_TOKEN
     * ERROR_UNEXPECTED_EXCEPTION java.lang.Exception
     */
    public Object getUnexpectedObject() {
        return unexpectedObject;
    }

    private static String toMessage(int position, int errorType, Object unexpectedObject) {
        StringBuilder sb = new StringBuilder();

        if (errorType == ERROR_UNEXPECTED_CHAR) {
            sb.append("Unexpected character (");
            sb.append(unexpectedObject);
            sb.append(") at position ");
            sb.append(position);
            sb.append(".");
        } else if (errorType == ERROR_UNEXPECTED_TOKEN) {
            sb.append("Unexpected token ");
            sb.append(unexpectedObject);
            sb.append(" at position ");
            sb.append(position);
            sb.append(".");
        } else if (errorType == ERROR_UNEXPECTED_EXCEPTION) {
            sb.append("Unexpected exception ");
            sb.append(unexpectedObject);
            sb.append(" occur at position ");
            sb.append(position);
            sb.append(".");
        } else if (errorType == ERROR_UNEXPECTED_EOF) {
            sb.append("Unexpected End Of File position ");
            sb.append(position);
            sb.append(": ");
            sb.append(unexpectedObject);
        } else if (errorType == ERROR_UNEXPECTED_UNICODE) {
            sb.append("Unexpected unicode escape sequence ");
            sb.append(unexpectedObject);
            sb.append(" at position ");
            sb.append(position);
            sb.append(".");
        } else if (errorType == ERROR_UNEXPECTED_DUPLICATE_KEY) {
            sb.append("Unexpected duplicate key:");
            sb.append(unexpectedObject);
            sb.append(" at position ");
            sb.append(position);
            sb.append(".");
        } else if (errorType == ERROR_UNEXPECTED_LEADING_0) {
            sb.append("Unexpected leading 0 in digit for token:");
            sb.append(unexpectedObject);
            sb.append(" at position ");
            sb.append(position);
            sb.append(".");
        } else {
            sb.append("Unkown error at position ");
            sb.append(position);
            sb.append(".");
        }
        return sb.toString();
    }

}
